Inhibition of rat uterine contractions by rat and human CGRP.
Effects of rat and human calcitonin gene-related peptide (r alpha CGRP and h beta CGRP, respectively) upon uterine contractile force were investigated using uterine horns from nonpregnant rats, r alpha CGRP and h beta CGRP were equipotent (pD2 = 8.85-9.09) in inhibiting spontaneous and electrically evoked uterine contractions. r alpha CGRP was relatively ineffective in inhibiting potassium-induced contractures of preparations from stilbestrol-pretreated rats. The use of selective antagonists established that r alpha CGRP did not release prostanoids, or release or act at receptors for catecholamines and histamine. The effects of the peptides were not significantly modulated by estrogen levels since pD2 values were similar (8.56-8.86) in field-stimulated preparations from rats in proestrus/estrus or metestrus/diestrus.
Pennefather
J N
JN
Department of Pharmacology, Monash University, Clayton, Victoria, Australia.
Reynoldson
N A
NA
Handberg
G M
GM
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001588:Benzoylcholine / Q000031:analogs & derivatives / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D003864:Depression, Chemical; D004054:Diethylstilbestrol / Q000494:pharmacology; D004558:Electric Stimulation; D004971:Estrus; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011899:Ranitidine / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D014590:Uterine Contraction / Q000187:drug effects*
D011994:Recombinant Proteins; D001588:Benzoylcholine; C016923:BW 172C58; D004054:Diethylstilbestrol; D001285:Atropine; D011899:Ranitidine; D015740:Calcitonin Gene-Related Peptide; D007545:Isoproterenol; D011188:Potassium; D007213:Indomethacin